That wasn't the only problem with the Arizona ban. The state law completely bypassed the seminal 1973 Roe v. Wade ruling, and measured the 20-week cut-off point from the date of a woman's last period, rather than from the date of conception. In other words, Arizona's abortion ban was effectively set at 18 weeks, rather than 20. And it allowed for exceptions only in event that the woman risked immediate death by continuing with the pregnancy, or a "substantial and irreversible impairment of a major bodily function."